Bond or tie for built-up crank shafts



Feb. 5, 1935. K. E. KYLEN BOND ORTIE FOR BUILT-UP CRANK SHAFTS FiledDec. 14, 1932 5 SheetsQ-Sheet 1 y a .Z a D INVENTOR I KARL ERIK KYLE/vJ4. 1 AM ATTORNEY Feb." 5, 1935. K. E. KYLEN 1,990,456

BOND OR TIE FORBUILT-UP CRANK SHAFTS Filed Dec. 14. 1952 5 Sheets-Sheet2 INVENTOR I KARL ERIK KYLE/v A; ATTORNEY Feb. 5; 1935. K. E. KYLEN1,990,456

BOND OR TIE FOR BUILT-UP CRANK SHAFT'S Filed Dec. 14, 1952 5.SheetS-Sheej s 54 v A so 3a INVENTOR I KARL ER/K/(YL su L ATTORNEY Feb.5, 1935. K. KYLEN 1,990,456

' BOND 0R TIE FOR BUILT-UP CRANK SHAFTS Filed Dec. '14. 1932 sSheets-Sheet 4 INVENTOR AML ERIK KY4 E'N BY M ATTORNEY Feb. s, 1935. K.E. KYLEN 1,990,456

BOND 0R TIE FOR BUILT-UP CRANK SHAFTS Filed'Dec. 14, 1932 5 Sheets-Sheet5 INVENTOR, KARL ERIK An EN ATTORNEY atented Feb. 5, i935 1,990,456 nounon rm gs gum-ore Karl Erik Kyln, Gottenborg, Sweden. assignor toAktiebolaget Svenska Kullagerfabriken, Gottenborg, Sweden, a corporationof Sweden Application December 14, 1932, Serial No. 647,163

In Sweden September 12,1932

7 7 Claims. (01. 74 -598) 5 another member by means of a plug or thelike inserted in the hole or cavity of the first mentioned member.

It has been previously known to make built-up crankshafts in which thecrank pins are made hollow and have a conical or tapering innersurface.The crank pin is then fixed to the web by means of a tapering plug,which is driven or pressed into the conical hole with such force thatthe crank pin is expanded in the web and held rigidly in position by thepressure between the members. Such method of building up crankshafts hasthe great disadvantage that it is impossible to definitely fix theamount of grip between the members, since the grip depends upon theextent to which the tapering plug is forced into the crank pin. Afterhaving had the crankshaft apart for repairs there is always a risk thatthe plug willnot be pressed home sufiiciently tight, and that the jointwill loosen, thereby destroying the crankshaft. This risk is, of.course, especially great when the repairs are made in a small machineshop by mechanics having insufficient experience with the type ofcrankshaft in question, or where proper machinery for the assembly ofthe crankshaft is not available.

The object of the present invention is to provide a device in which thegrip can be previously fixed, and in which the grip will always be thesame upon reassembling the crankshaft after repairs. For this purposethe plugs are made with a substantially cylindrical, instead of conical,

outer surface and with outer dimensions somewhat larger than the hole inthe member into which they are to be inserted. The difference indimensions will depend upon the amount of grip required. The greater thediflerence in dimensions, the greater will be the grip, but the greaterwill also be the force required to press home the plug. For this reasonit is desirable to make the grip conform to that which will be requiredby the conditions at hand.

The accompanying drawings illustrate a number of forms of plugs andmethods for assembling and dismantling the bond according to theinvention.

In which drawings:

Figure 1 shows a method of mountin a pair of plugs, one in each end of acrank pin having a through hole.

Figs. 2 to 9 each shows an end view and an axial section of atom of plugaccording to the invention.

Figs. 10 to 12 show methods of assembling plugs in crankshafts .in whichthe crank pin is made in one piece with one of the webs.

Fig. 13 shows a method of dismantling a plug by means of a tool such asis illustrated in Fig. 15.

Figs. 14 and 15 respectively show a side elevation and end view, of twotools for assembling and dismantling a crankshaft.

Figs. 16 and 17 show two methods of removing a plug.

Fig. 18 shows a crank shaft in which one plug is used in two joints.

Fig. 19 shows plugs consisting of two concentric annular members.

Fig. 20 shows the invention applied to fixing a gudgeon pin in aconnecting rod, and

Fig. 21 a device for increasing the friction in the joint.

The webs 1' in Fig. 1 are provided with through holes in which the crankpin 2 is to be fixed. The crank pin has a through hole in which theplugs 3 and 4 are inserted. The plugs are formed as annular members andare preferably chamfered at their inner ends to facilitate theirinsertion in the crank pin. A threaded bolt 5 is inserted through theholes in the plugs, which are forced home by drawing the nut 6. Betweenthe plugs and-the head of the bolt and the nut respectively are insertedwashers 8 and 9 having an outer diameter larger than the outer diametersof the plugs. These washers serve to prevent either or both of the plugsfrom being forced too far into the crank pin. r

The plug illustrated in Fig. 2 has been given a special form calculatedto facilitate its removal. The plug is removed with the aid of a tool ofthe kind shown in Fig. 14 and in the manner shown in Fig. 13. In theinner wall of the plug are two slots 11,- and on its inner end a crossslot'12, the width of the latter being about the same as the width ofthe former. threaded at one. end 14 and is provided at the other endwith a head 65. The head is provided with projections 15 so that itsform is nearly the same as that of the-hole in the plug. To remove theplug the head of the tool is passed'through the hole in the plug and thetool turned a quarter of a revolution so that the projections 15 engagewith the slot 12 as shown'in Fig. 13. Thisprevents the tool from turningrelative to the plug, thereby enabling the plugto be withdrawn by,

turning the nut. Anannular member 16 and a washer 17 are passed over thetool after which The dismantling tool 13 is.

the nut 18 is screwed on and drawn until the plug is removed.

Fig. 3 shows a plug which differs from the plug illustrated in Fig. 2 inthat it has four slots 18 and two cross slots 19. The plug is removed bymeans of the tool 20 illustrated in Fig. 15. The head of the tool isprovided with four projections 21. After the tool has been inserted inthe plug, it is turned an eighth of a revolution, and the plug can thenbe removed in the manner described in connection with Fig. 13.

Figs. 4 and 5 show two plugs of substantially the same shape and adaptedfor use in the respective ends of the same crank pin. The plugs 22 and23 are provided with circular through holes 24 and 25 and with crossslots 26 and 27. The plug 22 is removed in the manner shown in Fig. 13by means of a tool of the kind shown in Fig. 14. The diameter of theshaft of the tool is such that it fits the hole 24, and the diameter ofthe head across the projections is greater than the diameter of the hole24, but less than the diameter of the hole 25. The tool is passedthrough the hole 25 with the threaded end-first so that the projectionsengage with the slot 26. The plug 22 can then be removed in the mannerdescribed above. The other plug-23 can then be removed in a similarmanner by means of a larger tool of the same form, which is insertedfrom the opposite direction.

Figs. 6 and 7 show two forms of plugs adapted for use in pairs. The plug28, as shown in Fig. 6, is solid while the plug 29 is provided with acylindrical hole, as shown in Fig. 7. To dismantle the shaft the plug 28is first knocked or forced out by means of a mandrel inserted throughthe hole in the plug 29. The plug 29 can then be removed with the aid ofa mandrel of larger diameter inserted from the opposite direction.

Fig. 8 shows a plug 30 having a threaded hole. The plug is removed inthe manner shown in Figs.

' 16 and 1'7. As shown in Fig, 16, a. threaded tool 31 is screwed intothe plug, which is then removed with the aid of an annular member 16, awasher 1'7, and anut 18, in the manner described in connection with Fig.13.

According to Fig. 17 the crank pin is made in one piece with one of thewebs 33 and is partly hollowed out to receive a plug such as 30 forfixing the crank pin in the other web 34. The plug is forced out in thisinstance by means of a threaded tool 35 pressing against the bottom 36of the hollow in the crank pin.

The plugs illustrated in Figs. 2 to 8 are preferably hardened, but theform shown in Fig. 9 is most suitably made of unhardened material. Theplug is shown provided with an axial slot or channel 64. When it isdesired to remove the plug its center part is drilled, or turned outalmost to the bottom of the channel. Theremaining annular part of theplug will exert so little pressure against the inner wall of the crankpin that it can be easily removed.

Several methods of assembling crankshafts in which the crank pin is madein one piece with one of the webs are shown in Figs. 10 to 12. Accordingto Fig. 10 a threaded hole 38 is formed at the bottom of the hollow 37of the crank pin into which a tool 39 can be screwed. The hollow plug 40and the stop washer 41 are passed ovei the tool after which'the nut 42is applied and drawn. When the plug has been forced in as far as thestop washer will allow the tool 39 is screwed out of the threaded holeand removed.

According to Fig. 11 both thecrank pin 48 and the web 44 are drilledthrough to allow a tool 46 provided with a head to be passed through thehole. The plug can then be forced home in the manner described above.

In Fig. 12 the tool 47 is threaded to enable it to be screwed into athreaded hole in the web. The head of the tool 48 is made large enoughto perform the duty of a stop washer.

Fig. 18 shows a device in which a single plug 49 serves to fix the crankpin 50 to both the webs 51 and 52. The pin should preferably not beexpanded between the webs. The crank pin, or the plug, or both, aretherefore formed so that there will be a clearance 53 between them alongthis part of the crank pin.

Fig. 19 shows a device in which each plug consists of two concentricannular members. By this means it is possible to increase the pressureagainst the pin 54. When assembling the crankshaft the larger member 55is first pressed home in the pin 54 and expands the pin to fix it to theweb. The smaller member 56 is then inserted in the larger one 55 whichis expanded. This expansion is communicated to the pin 54,

,further increasing the friction between the pin and the web.

Fig. 20 shows the invention applied to a gudgeon pin having its bearingsin the piston bosses. The gudgeon pin 5'7 is fixed to the connecting rod58 by means of a plug 59 which is preferably made in one of the abovementioned forms to facilitate dismantling.

Fig. 21 shows an arrangement for increasing the friction and strength ofa joint. The plugs 60 are provided with flanges 61, which are secured tothe webs in some suitable manner, for instance by means'of rivets 62.If'desired, the flange 64 of a crank shaft plug may be secured byproviding it with a hole and allowing the crank pin to pro-' jectthrough this hole as shown at the left hand side in Fig. 21. By thesemeans a part of the torque can be transmitted from the web to the shaftby means of the friction between the plug and the shaft. Similar flangesas 65 also on the left hand side of Fig. 21, may be provided on theplugs 63 of the crank pin, if desired.

-By a suitable choice of the diameters of the plug and the hole in thecrank pin it is possible to adapt the grip according to therequirements. In cases where one of a pair of plugs is thicker than theother, the thinner plug may be made slightly larger than the other sothat the pressures exerted by both plugs will be substantially equal. Inorder to guard the pin from dangerous tension, and to increase thepressure between the pin and the surrounding part, the outer diameter ofthe pin can be made slightly greater than the diameter of the hole intowhich it is to be inserted. In this manner it'will be possible to obtainan initial pressure between the pin and the surrounding part which willcompress the end of the pin somewhat when it is driven, forced or shrunkin. When the plug is forced into place the pin is again expanded to itsoriginal diameter, thus sparing it from being subjected to considerabletension.

The invention is not confined to the forms illustrated, but can beapplied to a number of Having thus described my invention I claim anddesire to secure by Letters Patent:

1. A bond for a built-up crankshaft, one member having a bond receivingcavity and another member having a bond portion seated in such cavity,there being a plug receiving cavity in such bond portion formed with anuninterrupted cylindrical wall, and a plug havinga cylindrical outersurface seated in the hollow cavity in the said bond portion expandingit into the bond receiving cavity in the first named member, the plugconstituting the sole means for bonding the two members.

2. A bond for a built-up crt, one member having a bond receiving cavityand another member having a bond portion seated in such cavity, therebeing a plug receiving cavity in such bond portion formed with anuninterrupted cylindrical wall, and a plug having a cylindrical outersurface seated in the hollow cavity in the said bond portion expandingit into the bond receiving cavity in the first named member, the plugconstituting the sole means for bonding the two members, such plug beingformed with a hole extending axially through it for facilitating itsinsertion and removal.

3. A bond for a built-up crankshaft, one member having a bond receivingcavity and another member having a bond portion seated in such cavity,there being a plug receiving cavity in such bond portion formed with anuninterrupted cylindrical wall, and a plug having a cylindrical outersurface seated in the hollow cavity in the said bond portion expandingit into the bond receiving cavity in the first named member, the plugconstituting the sole means for bonding the'two members, such plug beingformed with a screw threaded hole extending axially through it forfacilitating its insertion and removal.

4. A built-up crankshaft comprising a pair of members each formed with abond receiving cavity, a hollow crank pin having its ends seated in suchcavity, the internal walls of the end portions of the pin being formedwith uninterrupted cylindrical surfaces, and plugs having cylindricalouter surfaces seated in the respective ends of the pin expanding theminto the cavities in the first named member, the plugs constituting thesole means for bonding the members. I

5. A built-up crankshaft comprising a pair of members each formed with abond receiving cavity, a hollow crank pin having its ends seated in suchcavity, the internal walls of the end portions of the pin being formedwith uninterrupted cylindrical surfaces, and plugs having cylindricalouter surfaces seated in the respective ends of the pin expanding theminto the cavities in the first named member, the plugs constituting thesole means for bonding the members, at least one of such plugs beingformed with a hole extending axially through it, such hole having one ormore maximum dimensions and one or more minimum dimensions.

6. A built-up crankshaft comprising a pair of members each formed with abond receiving cavity, a hollow crank pin having its ends seated in suchcavity, the internal walls of the end portions of the pin being formedwith uninterrupted cylindrical surfaces, and plugs having cylindricaloutersurfaces seated in the respective ends of the pin expanding theminto the cavities in the first named member, the plugs constituting thesole means for bonding the members, such .plugs being formed with holesextending axially through them, the maximum cross sectional dimension ofthe hole in one of the plugs being greater than the minimum crosssectional dimension of the hole in the other plug.

7. A built-up crankshaft comprising a pair of members each formed with abond receiving cavity, a hollow crank pin having its ends seated in suchcavity, the internal walls of the end portions of the pin being formedwith uninterrupted cylindrical surfaces, and plugs having cylindricalouter surfaces seated in the respective ends of the pin expanding theminto the cavities in the first named member, the plugs constituting thesole means for bonding the members, at least one of such plugs beingformed with a hole extending axially through it, the axially extendinghole in the plug having one or more cross sectional maximum dimensionsand one or more cross sectional minimum dimensions.

KARL ERIK KYLEN.

